Crushing and grinding mill



F. wmEnT. CRUSHING AND GRINDING MILL.

APPLICATION FILED )UNE 7, 1922.

IIALSQM,

if ff 7% Mmmm F. WRIEDT.

CRUSHING AND GRNDING MILL.

APPLICATION FILED JLJNE 1922.

Patented oct. 17, 11922,.

2 SHEETS-SHEET 2.

f6 an Patented @et il?, T922,

UNITED STATES rannte Parent carica@ FRIEDERIGJK WRIEDT, 01E" ALPHING'ION, VICTORIA, AUSTRALIA, ASSIGNOR I MIL@ MACHINERY COMPANY JPROPRIETARY LIMITED, 0F MELBOURNE, VICTORIA, AUS- THALIA.

CRUSHING AND @BINDING VIIII.

To all whom it may concern.'

Be it known that I, FREDERICK WRIEDT, residing at 50 Broomfield Avenue, Alphington, inthe State of Victoria, Commonwealth of Australia, have invented certain new and useful Improvements in Crushing and Grinding Mills; and I do hereby declare the following to be a full, clear, and exact description of the invention such as will enable others skilled in the art to which it appertains to make and use the same.

rIhis invention relates to an improved crushing and grinding mill for the treatment of granular materials or substances especially those having an organic nature or character such as grain, beans, seed, or the like; and it has been devised particularly to provide means whereby such materials may be rapidly disintegrated and pulverized continuously and efiiciently to a state of fineness or division.

In this invention the material to be treated becomes entrapped between the contiguous surfaces of a stationary supporting surface and one or more movable grinding elements and is thereby broken up and pulverized. The grinding elements are yieldingly pressed against the stationary supporting surface and as the material penetrates'therebetween the grinding elements are forced away from the stationary supporting surface in opposition to a retractive force such as the resil` ient action of a spring, or centrifugal action, or a combination of such actions.

Salient features of the invention reside in the provision of means whereby the entry of material between the stationary surface and movable grinding elements is facilitated, and of means whereby the efficiency of the grinding operation is increased and the movable elements are enabled to transfer or displace the material in a direction transversely to the direction of their motion. The leading portions of such movable element-is, chamfered or inclined at a required angle to the stationary supporting surface thereby forming a cuneiform space into which the material can readily enter. Moreover, the movable elements can be furnished with grooves or channels of tapered or other required form 'to increase the efficiency of the grinding action, and if these grooves or channels are disposed obliquely to the leading edge of the movable element they will displace the material transversely to the direct1on of motion of said elements.

' A special feature of the invention con-y sists in the grouping or arrangement of such movable grinding elements in parallel ser1es, the elements of each series being stepped or staggered in relationship to the elements of the adjoining series so that each element of any series is positioned in line with the space separating adjacent elements in the next series.

'Ihe obliquely disposed grooves on the elements comprising such parallel! series can be inclined in a common direction so that the material supplied to one side of a group of movable elements will be displaced transversely to their ldirection of motion and be discharged at the opposite side thereof into the spaces between adjacent grinding pads in the next series.

In one practical embodiment of the invention the stationary supporting surface can be arranged as a cylindrical casing around the inner periphery of which the movable elements consisting of a plurality of rotating grinding pads or shoes are adapted to travel. The rotating pads are arranged in parallel series and mounted upon a common operative shaft and they can be normally held in Contact with the casing by springs, and said pads can be pivoted or otherwise mounted in order that the actions of the springs may be assisted by centrifugal forces if so required.

rIhe material can be subjected to preliminary crushing or breaking down before being exposed to the pulverizing action of the rotating grinding pads and for this purpose crushing or abrading discs are employed one of which is mounted on the operative shaft carrying the grinding pads, and the other on the end of the cylindrical casing.

In a modification of the invention tapered grinding rollers may be mounted upon the operative shaft in lieu of the grinding pads or they may be used in conjunction therewith in required combination. These rollers bear yieldingly against the inner periphery of the casing and in consequence of the differential motion of their peripheries are very efficient for reducing the material to a finely powdered condition.

In order that the invention the object and nature of which have been set forth, may be with the l ings 16 readily understood, had to the accompanying sheets of explanatory drawings wherein Figure 1 .is a view in longitudinal section of a grinding mill constructed in accordance present invention.

Figure 2 is a view in transverse section taken 'on the dotted line 2 2 of Figure 1.

igure 3 is a view in elevation of the right hand end of the machine shown in Figure 1.

Figures 4 and 5, are views in perspective of grinding pads adapted for pivotal mount- Figure 6 is a sectional view of portion of a grinding machine showingv a radially guided grinding pad. v

Figure 7 is a sectional view of portion of a grinding machine showinga rotatably mounted tapered grinding roller.

In these drawings the numeral 10 designates a hollow cylindrical casing having covers 11 and 12, secured to its opposite ends, the assemblage of said casing and covers forming a closed cylindrical vessel 13, hereinafter termed the he pulverizing chamber 13 is supported at a convenient elevation upon brackets or legs 14.Which are connected integrally or otherl Wise to the covers 11 and 12 as illustrated in Figure 1. If preferred, the brackets 14 can be fixed to or formed integrally with the casing 10 so removed without disturbing'- the alignment of said casing.

An, operative shaft 15 supported in bearing chamber vand this shaft is provided with fast and loose belt pulleys 17 and 18 and with thrust bearin 19. V

One ormore spi ers 20, conveniently made as grooved or channeled castings or forg- I lngs are rigidly fixed to the shaft 15, and

upon pins 21 fixed in the spiders 20 are pivotally mounted grindin pads or shoes -or blades 22. Th mally maintained in contact with.- the inner periphery of the vcasing 10 b'ysprings 23 having one of theirfends secured to pins 24 on the spiders 20, and suitable means can be provided for adjusting the tension of saidl sprlngs.

`During the operation of the mill the springs 23 cause the pads 22 to exert a yielding pressure against the interior of the casing 10, and this pressure may be augmented by centrifugal action.by suitably formin and su portlng the pads 22. If the'grinfllr ing pa s 22 are formed so4 that under centrlfugal action they tend to turn in an outward direction about the pressure exerted' vby them upon the inside of the casing 10 will dependupon the speed at which the shaft is driven. 4

The pads 22 can, however, be so constructed and arranged that when they arevin reference will now be'.

effectively pulverizing chamber. ,b

thatthe end covers may be easilyl passes axially through the pulverizleading este grm ingpads are nor-v pivot pins 21 the' contact withrthe inner ing 10, their centres of lie in4 radial planes 21 and the axis of the shaft 15 in which case the pressure between the pads 22'- and the periphery of the casgravity or mass will passing through the pins casinglo will' beindependent of the velocity be approxigrinding pads 22 and the lnner surface .of

the casing 10,; and as the material penetrates therebetween the grinding pads 22 are forced away .from the casing against the retractive action of the springs 23 which may or may not be assisted'by lcentrifugal action above described'. The grinding pads V22 accordingly ride upon or pass over the material which is thereby subjected to a combination of squeezing crushed and pulverized.i In order to facilitate the entry of material etw'een the grinding'pads 22 and the casing 10 the leading portions ofthe former are charnfered or beveled'as shown in Figures 2 and 4; to

the material can readily enter. The cham'- fer vor bevel on the pads can be made straight or such chamfering or beveling can be formed to a required curvature.

The efficiency ofthe 'grindingv actionjof the pads 22 is ing portionof their working faces with l.a plurality of tapered grooves orrchannels 26. rlhe grooves or` channels 26 may be formed only 41n the chamfered portionsofthe pads is then due'only to the and grinding actions and isy greatly increased by provid- 22, and theyhave a maximum section at the l edge thereof and gradually decrease .1n size toward. and termlnate at the line of tionsof said pads-. y ,v i The grooves .or channels-'26 may be ,ar-

ranged parallelly to the ends of the vgrindin-g'.-

4the direction of motion of said grinding pads and the material will be displaced or moved towards the ends of the pads towards which said grooves incline.

The grooves or channels 26 may vary in Obliquity and in lform, number, extent, an'l arrangement in any required manner and their number and length may vary in diii'erent parts of a pad 22,'and they may be more numerous at one end thereof than at the oplosite end` to suit particular working con- -itions or materials.

. In Figure 5 agrinding pad is show-nl the `Junction of the cham'vfered and contact' por- Moreover, by formsurface of which conforms throughout to the curvature of the casing 10, and in which tapered grooves 27 are formed to facilitate the entry of material in lieu of chamfering the leading portions of said pad. 'llhese grooves 27 likewise increase the efficiency of the grinding actions and when disposed obliquely as shown serve to displace the material transversely in a similar manner to the tapered grooves or channels 26.

The grinding pads are arranged in series in parallel planes, preferably in staggered relation7 the pads of each series being positioned opposite to the spaces between adjacent pads of each adjacent series. `Moreover, the ends of each pad of a series, preferably, project into the spaces between the pads in the adjacent series; the opposite ends of each pad accordingly overlapping or being positioned in the path or line of motion of the adjacent series.

The grooves or channels 26 and 27 can be varied in form and extent in the different series; and may decrease in length in the successive series, preferably being of maximum length at the intake end of the pulverizing chamber 13. The widths of the chamferedportions of the pads in the successive series may likewise diminish and the widths of the contact portions thereof correspondin ly increase.

he grooves or channels 26, are preferably inclined in the same direction throughout the different series, and accordingly each series in addition to grinding the material simultaneously displaces it laterally and,

feeds it into the spaces between adjacent grinding pads in the succeeding series.

rlhe material, in this manner, is reduced in successive stages` to a required state of neness and is simultaneously displaced and transferred graduallyfrom one end to the other of the pulverizing chamber.

A discharge outlet 28 is provided in the end cover 12 towards which the common inclination of the' grooves or channels 26 is directed, and this outlet 28-is preferably furnished with a lateral chute 29 for convenient delivery of the pulverized material to a desired point.

rThe cover 11 opposite that provided with the discharge outlet is furnished with a feed hopper 30 into which the material to be ground and pulverized is placed and the said material gravitates from this hopper into a supply chamber 31 disposed concentrically about the shaft 15. A plurality of obliquely disposed or helical impellin blades or vanes 32 are fitted yto the portlon of the shaft which passes through the supply chamber 31 and these blades or vanes serve to thrust the material axiall through the supply chamber and into t e pulverizing chamber.

rlhe material'may be crushed and partially disintegrated before it is delivered to the pulverizing chamber and for simplicity and ease of handling the mill can be provided with crushing or abrading discs 33 and 34 which function to preliminaril.7 break downl the material during its passage from the feed hopper to the said pulverizing chamber.

The crushing or abra-ding discs are located in the feed ends of the machine anfl the disc 33 is rigidly secured to the cover 11 in any approved way and the coacting disc 34C is fixed to the shaft 15 by keys or like means.

rllhese discs 33 and 34 are dished conically on their inner sides and their conical faces are furnished with radially disposed bars or ribs arranged in any approved way. r1`he discs 33 and 34 are set at a predetermined distance apart, and the tapered annular space therebetween has a maximum width at the inner portions of said discs and uniformly diminishes or tapers to the outer portions thereof whereat it attains its minimum width in a peripheral opening 37.

The material is delivered by the impelling blades 32 through a central hole in the disc 33 into the radially taperingY space 36 and becoming closely packed therein by centrifugal action it is crushed and disintegrated by the abrading faces of the said discs.

rllhe crushed material emerges from the peripheral opening 37 and passes into the pulverizing chamber wherein it undergoes further treatment and is completely pulverized as previously described.

rlhe material when closely packed between the discs 33 and 34 and when being disintegrated thereby reacts upon said discs in such manner as to force them apart, thereby placing an end thrust on the shaft 15 which. is taken by the thrust bearings 19. The degree of fineness to which the material is re- -duced by the discs 33 and 34 depends upon the distance they are spaced apart, and the said distance can be regulated as required by adjusting nuts 35 on the ends of the shaft- 15 as required.

lfn lieu of the grinding pads 22, tapered or conical rollers 39 as shown in Figure 7 may be employed either alone or with said pads and an efficient combination consists of a plurality of series of grinding pads 22 with a terminal series of said tapered rollers. The rollers 38 are rotatably mounted on arms 39 pivoted on collars or Hanges 40 fixed to the shaft 15, and springs are employed to maintain the rollers bearing ,yieldingly against the casing 10 in the manner previously described.

r1`he tapered rollers 38 when moving in contact with the surface of the casing 10 have a differential motion about their axes which causes them to skid or slip upon the r culation of water.

' ation'but as CaSlIl suitably arranged pipes as 48,

surface ot the said casing land thereby Vsubject the material to an eicient grinding action. 4'Ihe rollers, quence of their conical construction, exert a translatory action on and causes the material to move parallelly to their axes and trans versely to theirpath of motion Iin a similar manner to the pads 22 previously described. The tapered rollers can be placed in line with the axis of the pulverizing chamber or slightly obliquely thereto as preferred'.

he pads and rollers have been described as plvotally mounted, but if preferred said pads and arms supporting the rollers can be formed with stems 43 which are adapted to be slidably mounted in radially disposed pockets or recesses 42 in lcollars or flanges 41 formed on or fitted to the operative shaft (see Figure 6). Springs 44 are disposed in the bottoms of the pockets and serve to yield-- ingly press the 'pads or rollers against the and normally maintain them in contact t erewith as previously described'.

`.During the treatment of the material -a considerable amount of heat is evolved, which if not removed -willrials so effect its nature as to'prevent the eliicient grinding and pulverizing 'of lthe same.

The temperature of the mill and the material being treated may be maintained with required limits by water cooling or by other sultable means and for this purpose the casing 10 is provided with a jacket 45 the space 46 therebetween being adapted for cir- Likewise the cover 11v on the feed end of the pulverizing chamber is furnished with a jacket 47 to prevent the overheatingvof the material as it)l is being acted upon by the'abrading discs. During the operation of the machine water is supf plied to the jackets 45 and 47 and is passed therethrough and removed therefrom 'by 49 and 450).

A m1ll constructed as above described embodies every feature o'f my invention and will be found thoroughly eflcient in loper- Iam aware that various altera'- tions and modifications may be made therein without departing from' thespirit and scope ofthe same I do not wish kto be understood as limiting myself -by the positive terms employed in the description, excepting the state of the art may' require.

I claim:

1'. In a grinding mill, astationary sup port for material to be ground provided with a peripheral concave inding surface, and` 'a series of grinding e ements movable over the support, having'convex peripheral grinding surfaces being provided ywith means for'facilitating the entry of material between the grinding t means.

elements and the support, and wi for displacing the material transversely to moreover, in conse-4- 'a series vable over said supp-ort, and means for exert- .with

with some matel grinding elements of the .in the terial to be groun .o hque grooves and being beveled on their such asv 4grinding surfaces provided wit said grinding elements meente the direction of motion of the grinding elements.

2. In agrinding mill', a stationary por-tl or the material to be with a peripheral concave supground, provided grinding surface, of parallel grinding elements moving a yielding pressure between the grinding elements and the support, said grinding ele-` ments having convex peripheral grinding surfaces provided with. means for facilitating the entry of material between the grinding 'elements and said support, and with lmeansfor displacing the material transversely to the direction of motion of said grinding elements and from one end to the other of said su port. n v

3. In a grin lng mill, a stationary Support for the material to be ground provided a peripheral concave grinding surface, and a series of parallel staggered and overlapping grinding elements movable over said support, said grmding elements having convex peripheral grindlng surfaces provided with means for facilitating the entry of material between the grinding elements and said support, and with means on each grinding element for displacing the material transversely-into the space between adjacent adjoining series.

a stationary supporti 4. In a grinding mill, for the materialv to be ground, one or more grinding pads,.. springs for pressing the grinding pads yieldingly against said support and driving ,means for propelllng the grinding pads over said support, said grinding pads being beveled on their leadin v faces, forming cuneal spaces between sald `eadlng faces land said" support, and with (grooves formed obliquelyin the grinding pa s. In a grindinglmill, a stationary support `form of a c. lindrical casing for magrinding` pads contacting with the cylindrical casing, springs maintaining a yieldin pressure betweenthe grinding pads and t e cylindrical casing, and' an `operative shaft for propelling said grindn pads around said cylindrical casmg, sai grinding pads being provided with leadlng edges, forming cuneal spaces between them and said casing.l A

6.In a grinding mill, a c lindrical casing having an internal perip eral 'grinding surface, grinding pads contacting therewith,

and an operative shaft for propelling thegrinding pads around. said casing; said grinding pads having convex eripheral oblique grooves which have `a common inclination towards one end of the casing, said casing havin a discharge opening at the en the grooves incline and a at the opposite end.

a grin ing mill, a combination of a cylindrical casing having an internal arc# shaped concave grindin surface, and a plurality of series of yieldingly supported grinding pads having convex peripheral grinding surfaces and adjacent thereto leading non-contact portions provided With oblique rooves, and an operative shaft for propel ing sald grinding pads around said casing; said grooves and non-contact sur faces decreasing in length and width respectively in the pads of each series as they are located progressively nearer the discharge end of the pulverizin chamber.

8. A grinding mil having a cylindrical pulverizing chamber, having a cover at one end, provided with a centrally disposed supply o ening, and a supply chamber connecte therewith, a driving shaft carrying grinding means within said cylinder, said shaft bein extended through said opening and supp y chamber, a conically dished grinding disc fixed to said cover and concentrically located about said supply opening, a4 similar grindin disc fixed to the driving shaft, said grinding discs having abrading surfaces on their conical faces and a peripheral discharge opening within said pulverlzing chamber between them, and impelling blades fixed to the driving shaft and located in said supply chamber.

9. In a grinding mill, a grinding pad having a chamfered leading portion, and obliquely disposed tapered grooves in the said chamfered portion.

10. In a grinding mill, a yieldingly supported grinding pad having grooves formed obliquely to its leadin edge.

ln testimony that cla1m the foregoing as my invention, l have signed my name in presence of two subscribing witnesses.

FREDERICK WRIEDT.

Witnesses:

CLUNA HARD, G. R. Gummi. 

